Project Summary: Previous research has repeatedly pointed to the transition to parenthood as an extremely stressful period that results in relationship distress and individual problems for many couples. Coparenting and couple functioning have been identified as critical constructs during this period, especially as they affect infant development. However, previous research has relied on naturalistic longitudinal designs to examine the impact of these variables on infant development. Only through an experimental design can one examine the reciprical causal effects of coparenting, couple functioning, and infant development. Once the causal relationship between variables is understood, targeted interventions for the transition to parenthood can be developed. The present study will randomly assign 90 couples to a coparenting-focused intervention, a couple-focused intervention, and a information-control group and follow them and their infant through a year after birth. The two active interventions will consist of 2 90-minute sessions before birth and 2 90-minute sessions approximately 3.5 months after birth. The information control group will consist of a single 90- minute session before birth. Couples will be assessed in the third trimester (but before the intervention), at 1 month, at 3 months, at 6 months, and at 1 year after birth. These assessments will include self-report and observational measures of coparenting and couple functioning as well as parent-report measures of infant emotional, social, and language development. The present study has two central aims: (1) Experimentally test causality of direct and indirect contributions of couple relationship functioning and coparenting on infant development during the first 12 months and (2) conduct a study of the relative effectiveness of couple- or coparenting-oriented secondary prevention interventions for moderate-risk couples during pregnancy. Relevance: Couples having their first child find the experience extremely stressful; furthermore, many couples begin to experience serious relationship or individual problems (e.g., depression, anxiety) after the birth of their child. These problems, in turn, negatively affect the development of their child. This study seeks to better understand the relative roles of couple functioning (e.g., marital satisfaction) and coparenting (e.g., parental support) and use these findings to inform future interventions for the transition to parenthood. [unreadable] [unreadable] [unreadable]